A Stability Indicating RP-HPLC for the Simultaneous Estimation of Hydrochlorothiazide, Amlodipine Besylate and Telemisartan in Bulk and Pharmaceutical Dosage Form

A stability indicating RP-HPLC method was developed for the simultaneous estimation of the anti hypertensive drugs Hydrochlorothiazide, Amlodipine Besylate and Telemisartan. These drugs were subjected to stress studies under different conditions as per ICH guidelines. The separations were carried out using C-18 reverse phase column ( Agilent ODS UG 5 column, 250mm x 4.5mm, 5 mu m) employing Acetonitrile and Acetate buffer ( 60: 40 v/v) as mobile phase and pH adjusted to 5 at flow rate of 1ml/min was used for separation, detected at 333 nm. The drugs were exposed to acidic, alkaline, oxidative, thermal and photolytic conditions and the stressed samples were analyzed by the proposed method. Degradation studies showed that all the three drugs were degraded under oxidative, thermal and photolytic conditions, negligible degradation observed under acidic, alkaline conditions. Analytical validation parameters such as specificity, linearity, accuracy, precision, Ruggedness and Robustness were determined and relative standard deviation of all the parameters were found to be less than 2%. Hence this method was found to be stable indicator that can be used for the routine analysis of these drugs in the bulk and combined tablet dosage form.